A variety of applications exist in which two or more sensors are used in one control or monitoring system. Typically, each of the sensors is monitored in parallel. In certain critical applications, for example, two or more mutually redundant sensors monitor the same target simultaneously. A selector is used to determine which of the their outputs is deemed most reliable, and the selected output is used for system control.
In other applications, an array of sensors is used to obtain a comparative or other composite measurement from which an inference can be drawn. By averaging measurements from such an array, for example, one can determine an areal average of a statistic of interest such as height or magnetic flux density. By comparing sensor outputs, also, one can also determine which sensor is nearest or best aligned with a feature of interest.
Recently, certain applications have arisen in which access to a sensor (or its data path) is scarce. This may be the case where data bandwidth, component life, or available energy is limited. Although time multiplexing is generally available as a means for sharing a resource, its application to sensors has thus far been limited to contexts with exceedingly simple geometries. Accordingly there is a need for more a more versatile way to use sensors efficiently, on an intermittent basis.